Add an integration test for kythe support with bug fixes

pkg/analyzer_plugin/test/plugin/kythe_mixin_test.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:async';
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer_plugin/plugin/kythe_mixin.dart';
@@ skipping 65 matching lines @@
 
   PrioritizedSourceChange createChange() {
     return new PrioritizedSourceChange(0, new SourceChange(''));
   }
 
   @override
   List<EntryContributor> getEntryContributors(String path) {
     KytheVName vName = new KytheVName('', '', '', '', '');
     return <EntryContributor>[
       new _TestEntryContributor(<KytheEntry>[
-        new KytheEntry(vName, '', vName, '', <int>[]),
-        new KytheEntry(vName, '', vName, '', <int>[])
+        new KytheEntry(vName, '', target: vName),
+        new KytheEntry(vName, '', target: vName)
       ]),
       new _TestEntryContributor(
-          <KytheEntry>[new KytheEntry(vName, '', vName, '', <int>[])])
+          <KytheEntry>[new KytheEntry(vName, '', target: vName)])
     ];
   }
 
   @override
   Future<EntryRequest> getEntryRequest(
       KytheGetKytheEntriesParams parameters) async {
     AnalysisResult result = new AnalysisResult(
         null, null, null, null, null, null, null, null, null, null, null);
     return new DartEntryRequestImpl(resourceProvider, result);
   }
 }